Some devices like iPad (at least some of them) don't support the M4A sound files generated by the HTML5 exporter by default.
The build 282.3 has a new option in the preferences (General tab / select the HTML5 exporter) to build MP3 files instead of M4A files if lame_enc.dll is installed in the data/runtime/flash folder.
If you want to build MP3 sounds instead of M4A :
- If the SWF exporter is installed, you have nothing else to do as it contains lame_enc.dll in data/runtime/flash. Just make sure the option above is selected.
- If the SWF exporter is not installed, you need to find and download lame_enc.dll from the Internet and copy it to the data/runtime/flash folder of CF 2.5 (for example you can find it in http://lame.buanzo.org/, download the zip file for Wndows). And make sure the option above is selected.